a. Field of the invention
The present invention relates to a lubricating oil pump and, more particularly, to a plunger-type lubricating oil pump.
B. Description of the prior art
Some of known plunger-type lubricating oil pumps are arranged so that the delivery varies in proportion to rotational speed of the plunger and others are arranged so that the delivery can be controlled by adjusting operation from the outside. In the former type of pumps, a lead portion for giving reciprocating movement to the plunger and a pump chamber are formed at positions separate from each other. In the latter type of pumps, a delivery control means is arranged at one end of the plunger and the pump chamber is arranged on the other end. Both types of pumps therefore have disadvantages that the cost of production is comparatively high and, moreover, that the pump as a whole becomes large in size compared with its delivery.